Open AccessOverexpression, purification and crystallization of a choline‐binding protein CbpI from Streptococcus pneumoniae
Author(s) -
Paterson Neil G.,
Mitchell Timothy J.,
Isaacs Neil W.,
RiboldiTunicliffe Alan
Publication year - 2006
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309106020616
Subject(s) - tetragonal crystal system , crystallization , crystallography , streptococcus pneumoniae , chemistry , choline , affinity chromatography , peg ratio , size exclusion chromatography , fast protein liquid chromatography , crystal structure , chromatography , high performance liquid chromatography , biochemistry , enzyme , organic chemistry , finance , economics , antibiotics
The choline‐binding protein CbpI from Streptococcus pneumoniae is a 23.4 kDa protein with no known function. The protein has been successfully purified initially using Ni–NTA chromatography and to homogeneity using Q‐Sepharose ion‐exchange resin as an affinity column. CbpI was crystallized using PEG 3350 as a precipitant and X‐ray crystallographic analysis showed that the crystals belonged to the tetragonal space group P 4, with unit‐cell parameters a = b = 83.31, c = 80.29 Å, α = β = γ = 90°. The crystal contains two molecules in the asymmetric unit with a solvent content of 55.7% ( V M = 2.77 Å 3 Da −1 ) and shows a diffraction limit of 3.5 Å.